Metal Investment Casting Foundry with Lost Wax Process

During the investment casting process, a wax pattern is coated with a ceramic material, which, when hardened, adopts the internal geometry of the desired casting. In most cases, multiple parts are cast together for high efficiency by attaching individual wax patterns to a central wax stick called a sprue. The wax is melted out of the pattern – which is why it is also known as the lost wax process – and molten metal is poured into the cavity. When the metal solidifies, the ceramic mold is shaken off, leaving the near net shape of the desired casting, followed by finishing, testing and packaging.

Investment castings are widely used in pumps and valves, automobile, trucks, hydraulics, forklift trucks and many other industries. Because of their exceptional casting tolerance and exellent finish, the lost wax castings are used more and more. Especially, the stainless steel investment castings play a vital important role in the shipbuilding and boats because they have strong anti-rust performance.

According to the different binder materials used for making the shell, the investment casting could be divided into silica sol casting and water glass casting. The silica sol investment casting process have better Dimensional Casting Tolerances (DCT) and Geometrical Casting Tolerances (GCT) than water glass process. However, even by same casting process, the Tolerance Grade will be different from each cast alloy due to their various castability. Our foundry would like to talk with you if you have special request on the required tolerances. Here in the following are the general tolerances grade we could reach both by silica sol casting and water glass casting processes separately:

✔ DCT Grade by Silica Sol Lost Wax Casting: DCTG4 ~ DCTG6

✔ DCT Grade by Water Glass Lost Wax Casting: DCTG5 ~ DCTG9

✔ GCT Grade by Silica Sol Lost Wax Casting: GCTG3 ~ GCTG5

✔ GCT Grade by Water Glass Lost Wax Casting: GCTG3 ~ GCTG5.

Almost most of the ferrous and nonferrous metal and alloys could be cast by investment casting process. But, at our lost wax casting foundry, we mainly cast the carbon steel, alloy steel, stainless steel, super duplex stainless steel, gray cast iron, ductile cast iron, aluminium alloys and brass. Additionally, certain applications require the use of specialized other alloys used primarily in harsh environments. These alloys, such as Titanium and Vanadium, meet the additional demands that might not be achieved with standard Aluminum alloys. For example, Titanium alloys often are used to produce turbine blades and vanes for aerospace engines. Cobalt-base and Nickel-base alloys (with a variety of secondary elements added to achieve specific strength-strength, corrosion-strength and temperature-resistant properties), are additional types of cast metals.

Yes, we could provide the 3.1 material certificate if you request.

The investment casting is also called precision casting because it have much better surface and higher accuracy than any other casting process. Especially for the silica sol casting process, the finished castings could reach the CT3 ~ CT5 in geometrical casting tolerance and CT4 ~ CT6 in dimensional casting tolerance. For the casings produced by investment, there will be less or even no need to make the machining processes. To some extent, the investment casting could replace the rough machining process.

The investment casting gets its name because the patterns (wax replicas) is invested with the surrounded refractory materials during casting process. The "invested" here means being surrounded. The wax replicas should be invested (surrounded) by the refractory mateials to withstand the high temperature of the flowing molten metals during casting.